113
6–4–1
Error List for Special I/O Units
Waiting for Special I/
O Unit start-up.
Special I/O Unit has a hardware
malfunction.
PC will not begin operation.
Replace the abnormal Special I/O Unit
with a new Unit.
(The abnormal Unit displays only ”$”
when the I/O table is read.)
Set unit numbers so that each is used
only once.
(Unit numbers can be accessed by
reading the I/O table.)
Obtain the abnormal unit number by
reading AR bits 0000-0009 and remove
the cause of the error. Then restart by
turning on, then back off, the appropri-
ate restart bit (AR bits 0100-0109). If
the Unit does not recover normal oper-
ation after restarting, replace it with a
new one.
Error
Causes of Abnormality and
Operating Status
Correction
Too many Special I/O
Units.
Same unit number has been
assigned to more than one
Special I/O Unit.
PC will not begin operation. SR
bit 25415 is ON.
Refreshing between the CPU
and the Special I/O Unit was
not executed correctly.
Only the abnormal Unit will stop
operating. SR bit 25415 is ON.
Error in Special I/O
Unit.
6–4–2
AR Area Error and Restart Bits for Special I/O Units
Error Flags
The following error flags will turn ON when the same unit number is assigned
to more than one Special I/O Unit, or when the refreshing operation between
the PC and the Special I/O Unit is not executed properly.
Bit Unit Number
AR 000
0
AR 001
1
AR 002
2
AR 003
3
AR 004
4
AR 005
5
AR 006
6
AR 007
7
AR 008
8
AR 009
9
Troubleshooting from the PC
Section 6–4
